Newcastle United boss Eddie Howe has indicated that he will not have unlimited money to spend this January.
The Magpies did put in £200 million on new players last January and this past summer.
That included £63 million for record signing Alexander Isak from Real Sociedad.
Asked about such spending, Howe told reporters during a press conference: "I think that is unsustainable, Financial Fair Play, I know it is mentioned a lot. That will guarantee that.
"I think you have to be mindful of that fact. That's where we need to improve, to make sure we don't have to go to the transfer market and spend that money. Can we produce more of our own players? Can we improve everything we deliver?
"Not just transfers. It can be very difficult for all clubs to spend that money on a consistent basis."
Howe added on the fans accepting limited spending: "I would love to think so, they have a level of understanding, I am sure they do. It is a difficult one for me to comment on. Dan has made that comment and I take my information from them.
"We go into the next window knowing it will be very different to the last one. No two windows are the same. We know we are going to have to control our spending for sure."
